Improvement in mechanical jacks



j UNITED STATESI PATENT' OFFICE.

AMOS JONES, OF LEBANON, NEV HAMPSHIRE, ASSIGNOR TO HIMSELF AND SOLON M. DAVIS, OF SAME PLACE.

Specification forming part of Letters Patent No. 21,107, dated August 3, 1858.

To @ZZ whom t may concern.-

Beit known that I, AMOs JONES, of Lebanon, in the county of Grafton and State of New Hampshire, have invented a new and Improved Mechanical Jack; and I do hereby declarethat the following is a full and eXact description thereof, reference being had to the accompanying drawings, making a part of this specification.

My improved jack is exceedingly simple in its construction, and is principally intended to be used for elevating and supporting either end of the axles of various kinds of vehicles preparatory to removing the w heels therefrom for the purpose of applying some lubricating material to the journals of said axles.

Figure l of the accompanying drawings is a perspective View representing my improved jack in the act of supporting the end of an axle-tree, and Fig. 2 is a side elevation of said jack with its lever in rest.

The said jack is composed of the head-piece A and the toothed shank B, which projects from the central portion of said head-piece, and it is operated by the lever OQ Rackplates D D are secured to the opposite edges of the shank B in any suitable manner.

The shape and arrangement of the teeth which project from the rack-plates D D are clearly represented by the drawings. Each tooth has a straight edge and a curved or inclined edge. The straight edges of the rackteeth project at right angles from the broad faces of the shank B, and the position of the series of teeth which project from one side of said shank is the reverse of that of the series of teeth which project from the opposite side of the same. The lever C is of such a shape that it will work freely in the notches between each pair of rack-teeth.

Vhen the end of a`n axle or any other object is to be elevated by the aid of my improved jack, the said instrument must be placed in the proper position in relation to said axle, which will be with one edge of the shank B facing the object to be raised and but a few inches distant therefrom, .as represented by Fig. l. Then the lever O must be placed in an inclined position upon the straight edge of the rack-tooth, which is at the proper elevation to serve as the fulcrum of said lever when its short end is inserted under the axle or other object to be raised. Then by drawing down the long end of said lever over the inclined faces of the series of :rack-teeth nearest to the operator the axle or other object will be elevated, and by passing said lever under o-ne of said teeth the object elevated will be retained at any desired elevation until the lever is detached from its position beneath the said retaining-tooth.

The application of my improved jack to the raising of different objects Will be readily understood by all persons possessing ordinary ingenuity.

The staple d, which projects from one side of the shank B, and the mortise ein the headpiece A receive the lever C and retain it A safely in place whenthe jack is not in use.

IVhat I claim as my invention, and desire to secure by Letters Patent, is

Constructing an improved jack by combining a double-toothed shank B with a suitable head-piece A, when the teeth of said shank are arranged in such a manner as to furnish the necessary fulcrums and catches for the operating-lever O in the performance of its appropriate functions, substantially as herein set'forth.

The above specification of my improved mechanical jack signed and witnessed this 19th day of April, 1858.

AMOS JONES.

Witnesses;

E. J. DURANT, IV. P. McFEE. 

